Mossel Bay seawater desalination plant

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The seawater desalination plant Mossel Bay ( English Mossel Bay seawater desalination plant ) is used for drinking water supply of the municipal area of Mossel Bay on the South African coast of the Indian Ocean and the process water demand of PetroSA. It is the largest seawater desalination plant in the country for drinking water production . It started operations in 2011. The project had a budget of 210 million rand to set up , the final cost was given as 194.9 million rand.

business

Because of its high maintenance costs of 200,000 Rand per month, the plant is not operated continuously. The production of drinking water on the basis of this technology is associated with high energy costs, which in this case accounts for 50% of the total operating expenses.

The desalination plant has a daily production capacity to deliver 10 megaliters (million liters ) of drinking water for the Mossel Bay Local Municipality and 5 megaliters of industrial water for PetroSA.

The main customers are the residents of the region and the petrochemical production site of PetroSA, which is also the largest employer in the municipality.

technology

After removal from the sea, macroscopic floating cargo, such as grains of sand, seaweed and shell debris from marine animals, must be cleaned . The geological environmental conditions and the water quality of the resource are decisive for the expenditure in the cleaning process. Ideally, constant values ​​of the salt content, small temperature fluctuations and a low pH value are advantageous. When treating raw water, algae must also be removed. The raw water is purified by blowing air and centrifugal separation. The actual desalination is carried out using reverse osmosis . The water then receives an aftertreatment with carbon dioxide and calcium hydrogen carbonate , in which a desired salt content with a defined concentration and the pH value are set under controlled conditions. This measure serves to reduce adverse corrosive effects in the lines to the end user.

Veolia Water Technologies , based in Johannesburg , was commissioned to operate the Mossel Bay seawater desalination plant . It is a subsidiary of the French Veolia Environnement SA. The company is a world leader in RO technology (RO for Reverse Osmosis ). In South Africa, Veolia operates 7 desalination plants based on this technology, Mossel Bay is the largest.

history

The initiative for this project came from the South African oil company PetroSA. In Mossel Bay, the company uses a synthesis process to produce fuel from natural gas . This process requires steam, which was previously generated with water from the nearby Wolwedans Dam . This dam also supplies the community with drinking water. As a result of the persistently low rainfall in southern Africa for several years, the water level in the dam was also low. In May 2010 the available storage volume was 12.5% ​​and the drying up of the reservoir was predicted for the following October. In what was then Eden District Municipality , which also included Mossel Bay, the drought had already reached such an extent that a disaster had to be declared. At that time, PetroSA spent 22.5 million rand under these conditions to build a wastewater treatment plant operated by the community of Mossel Bay.

However, this looming shortage of water prompted PetroSA to initiate the necessary precautions for a safe water supply alternative earlier than originally planned. The choice fell on a seawater desalination plant, the construction of which was only planned for 2014. As part of the project planning, PetroSA made a pro rata investment of 80 million rand. The overall financing for the construction of the plant was the responsibility of three partners, the South African Ministry of Finance, PetroSA and the municipality of Mossel Bay. With this project, a production capacity of 200,000 liters per hour or around 5 megaliters per day was estimated. The date of commissioning was planned for November 2010. The facility was built near the PetroSA logistics center and in the Voorbaai district not far from the port of Mossel Bay.

Individual evidence

  1. ↑ a b c eNCA: Mossel Bay desalination plant could save drought-stricken towns . News from September 8, 2017 on www.enca.com (English)
  2. ^ Western Cape Government: Desalination Plant structurally complete . News from May 25, 2011 on www.mosselbay.gov.za (English)
  3. ^ A b c Veolia Water Technologies: Mossel Bay, Western Cape - Seawater Desalination . on www.veoliawatertechnologies.co.za (English)
  4. ^ Western Cape Government: Desalination plans within budget . News from February 24, 2011 on www.mosselbay.gov.za (English)
  5. ^ A b c Western Cape Government: Mossel Bay's desalination plant gets top award . News from August 24, 2011 on www.mosselbay.gov.za (English)
  6. ↑ Veolia Water Technologies: Reverse Osmosis Desalination . at www.veoliawatertechnologies.com (English, PDF) PDF document p. 5, 10
  7. ↑ Dylan Slater: Amid growing water worries, desalination option enters SA's supply debate . News from August 11, 2017 on www.engineeringnews.co.za (English)
  8. ↑ Independent Media: PetroSA plans R80m Mossel Bay desalination plans . News from May 27, 2010 on www.iol.co.za (English)

Web links

  • Veolia Water Technologies: website . on www.veoliawatertechnologies.co.za (English)